1. Field of the Invention
The present invention relates to the art of electrical connectors, and more particularly to a pick-up cap for use in a central processing unit (CPU) socket to facilitate operation.
2. Description of the Related Art
In order to accurately position a CPU socket on a printed circuit board (PCB), the CPU socket is carried to the PCB by a vacuum device which sucks a pick-up cap connected with the CPU socket. As can be seen from FIGS. 6 and 7, a pick-up cap 4 has an upper surface 40 and a bottom surface 41, and a plurality of legs 42 projecting downwardly from the bottom surface 41. The hooks 42 are fit in corresponding openings 311 of a cover 31 of a CPU socket 3 and engaged with a stopping face 312 defined in the opening 311 thereby securing the pick-up cap 4 on the CPU socket 3. Consequently, the CPU socket 3 is carried by a vacuum device (not shown) sucking the top surface 40 of the pick-up cap 4 and is accuratedly located on the PCB.
However, the hook 42 has to be bent laterally to escape the stopping plane 312 during its downwardly engaging process. If deformation of the hook 42 is too great, it will break off from its weakest point, thereby leading to failure of the pick-up cap 4 to connect with the CPU socket 3. The copending application Ser. No. 09/909,584 having the same assignee with the invention, discloses a pick-up cap to be engaged with and disengaged from the moveable cover when the cover is in different positions. Anyhow, this style socket and cap are used for a relative large dimension design where the hooks are substantially surrounding the contact area thereof. For the relatively small dimension design as shown in FIGS. 6 and 7, such an arrangement can not fit thereto because there is no available space on the outer sides of the contact areas for disposing such hooks. Thus, a new pick-up cap design having the similar advantage of the aforementioned copending Ser. No. 09/909,584 application while being used for the small sized socket as shown in FIGS. 6 and 7, is earnestly desired. Moreover, another disadvantage of the design shown in FIGS. 6 and 7, is A that the available suction area is relatively limited because of the latch positions (referring to the copending application Ser. No. 10/040,533 with the same assignee as the invention).
An object of the present invention is to provide a CPU socket assembly with an improved-pick-up cap having a retention mechanism which can be easily and reliably assembled to the CPU socket.
Another object of the present invention is to provide a method for mounting a CPU socket on a PCB through a vacuum device and a pick-up cap.
In order to achieve the objects set forth, a pick-up cap in accordance with present invention for assembled to a CPU socket is provided. The socket includes a base and a cover slidably stacked on the base to movable between an open position and a closed position. The base and the cover both has openings defined thereof, such openings are completely overlapped with each other at the open position and are partially overlapped with each other at the closed position. The pick-up cap has a flat top surface and a bottom surface, and a corresponding number of legs projecting downwardly from the bottom surface. Each leg forms a hook at a free end thereof.
In assembly, the openings of the cover are firstly overlapped the openings of the base completely, then the hooks of the legs are freely inserted through the openings of the cover and reaches the openings of the base. Subsequently, the cover slides laterally with regard to the base to make the openings of the cover partially overlap the openings of the base, so that the openings of the cover engage with the hooks of the legs. Finally, a vacuum device (not shown) sucks the top surface of the pick-up cap to mount the socket at a predetermined position on a PCB.